Topographic anatomy and operative surgery of the small pelvis. Topographic anatomy of the pelvis of a woman. Bladder and ureters

Rectum. In the female pelvis anterior to the rectum are the uterus and vagina. In the peritoneal floor of the small pelvis, between the rectum and the uterus, there is the lowest part of the pelvic cavity - the recto-uterine cavity, exca-vatio rectouterina, where, as a rule, loops of the small intestine are located. In the subperitoneal floor, the rectum is adjacent to the vagina in front. The peritoneal-perineal aponeurosis in women, or septum gestovaginale, is represented by a thin, sometimes loose plate that separates the rectum and vagina and is attached with its lateral sections at the level of the crusoid-iliac joints. The lymphatic vessels of the rectum in women form connections with the lymphatic vessels of the uterus and vagina. The place of these connections is the rectovaginal septum, regional iliac lymph nodes.

Bladder and ureters. In the female pelvis, the bladder lies deeper in the pelvic cavity than in men. In front, it, like in men, adjoins the pubic symphysis and is fixed to it by the pubic-cystic ligaments. Behind it is adjacent to the uterus and in the subperitoneal space - the vagina. The bottom of the bladder rests on the urogenital diaphragm. C. laterally to the base of the bubble is adjacent the muscle that lifts the anus, m. levator ani, to the top of the bladder - loops of the intestines. The lymphatic vessels of the bladder in women form direct connections with the lymphatic vessels of the uterus and vagina at the base of the broad ligament of the uterus and in the regional iliac lymph nodes.

The ureters in the female pelvis, as well as in the male, are located under the peritoneum and are surrounded by paraurethral tissue, have their own fascial case. In the cavity of the small pelvis, the ureters first lie on the side wall of the pelvis, on the anterior surface of the internal iliac artery, anterior to the aa. uterinae, then in the thickness of the base of the broad ligaments of the uterus. Here the ureter crosses again a.uterina, located under it and 1.5-2 cm from the internal pharynx of the cervix. Further, the ureters are adjacent to the anterior wall of the vagina for a short distance and flow into the bladder at an acute angle.

It is possible to expose the ureter at the level of the border line at the border of its posterior third and in the cavity of the small pelvis, in the ovarian fossa, fossa ovarica, bounded from above by the external iliac vessels, from behind and the medial by the internal iliac vessels, and in front by the line of the pelvic attachment of the wide ligament of the uterus. The same landmarks serve to expose and ligate the uterine artery.

Uterus, uterus. The uterus is located in the small pelvis between the bladder in front and the rectum in the back. It consists of two sections: the upper - the body of the uterus and its bottom, the lower - the cervix. In the neck, supravaginal and vaginal parts are distinguished. Between the body and the cervix, an isthmus is isolated, isthmus uteri. In relation to the main longitudinal axis of the pelvis, the uterus is usually tilted forward - anteversio, the body of the uterus in relation to the neck is also tilted forward - anteflexio. The ratio of the peritoneum to the uterus, see above. On the sides of the uterus, the sheets of the peritoneum, converging, form duplications - the right and left broad ligaments of the uterus, ligg.lata uteri dextrum and sinistrum, located in the frontal plane. In the free edge of the wide ligaments of the uterus, the fallopian tubes, tubae uterinae, are laid. At the base of these ligaments, from the cervix (the level of the internal os) to the side wall of the pelvis, the muscular-fibrous bundles of the main ligament of the uterus, lig. cardinale. Front

leaf of the broad ligament covers the round ligament of the uterus, lig. teres uteri, running from the corner of the uterus to the deep inguinal ring. It consists of fibromuscular fibers and contains the artery of the round ligament of the uterus, a lig. teretis uteri (from a. epigastrica inferior). The ovary is fixed to the posterior leaflet of the broad ligament of the uterus with the help of the mesentery (mesovarium). The part of the broad ligament between the fallopian tube and the fixation line of the mesentery of the ovary is called the mesentery of the fallopian tube, mesosalpinx. It contains rudimentary formations: the ovarian epididymis, ero-ophoron, and the periovary, paraoophoron, which disappear with age. These vestigial organs are sometimes the site of the formation of malignant tumors and intraligamentary cysts.

The fixing apparatus of the internal genital organs of a woman is a ligament that is in close connection with the parietal and visceral fascia of the pelvis (Fig. 119). They consist of connective tissue strands and smooth muscle fibers. These include the main ligaments, ligg-cardinalia ^ sacro-uterine, ligg. sacrouterina, pubic vesicles, ligg. pubovesicalia, continuing in the vesicouterine, ligg. vesicouterina. The supporting (supporting) apparatus of the internal genital organs forms a group of muscles and fasciae of the pelvic floor. In the fixation of the vagina, not only the fibers of the deep transverse perineal muscle are involved, but also the medial bundles of the muscle that lifts the anus. The suspension apparatus is formed by round and wide ligaments of the uterus, ligg. teres uteri and ligg. lata uteri.

In the subperitoneal floor of the small pelvis around the cervix and vagina, as well as between the sheets of the broad ligament of the uterus, there is a layer of parametric fiber.

The blood supply to the uterus (Fig. 120) is carried out by two uterine arteries, aa-uterinae (from aa-iliacae intemae), ovarian arteries, aa. ovaricae (from the abdominal aorta), and the arteries of the round ligament of the uterus, aa. lig. teretis uteri (from aa. epigastricae inferiores). The beginning of the uterine artery is covered from above by the ureter. At a distance of 4-5 cm downward from the place of origin, the uterine artery enters the main ligament of the uterus, which lies at the base of the broad ligament, and, not reaching 2 cm to the cervix, crosses the ureter from above. At the lateral edge of the uterus, the artery gives off the vaginal branch, r.vaginalis, rises up the lateral edge of the uterus and anastomoses in a broad ligament with the ovarian artery and the artery of the round ligament of the uterus. The veins of the uterus form the uterine venous plexus, plexus venosus uterinus, located on the sides of the cervix and in the parauterine tissue. It widely anastomoses with the venous plexus of the vagina, plexus venosus vaginalis, veins of the vulva and other veins of the pelvic organs. The outflow of venous blood goes through the uterine veins into the internal iliac veins and through the ovarian veins into the inferior vena cava.

Regional lymph nodes of the cervix are nodes located along the iliac arteries and on the anterior surface of the sacrum. Lymphatic outflow from the body of the uterus occurs in the lymph nodes located in the circumference of the aorta and inferior vena cava. From the bottom of the uterus, through the lymphatic vessels of the round ligament of the uterus, the lymph partially flows to the inguinal lymph nodes. At the base of the broad ligament of the uterus, the efferent lymphatic vessels of the body and the bottom of the bladder merge with the lymphatic vessels of the body and cervix. The common plexus of lymphatic vessels for the body, cervix and rectum is located under the peritoneum of the recto-intestinal depression. The innervation of the uterus and vagina is carried out by an extensive utero-vaginal nerve plexus, plexus uterovaginalis, which is the middle section of the paired lower hypogastric plexus (pelvic), plexus hypoga-stricus inferior (pelvinus).

Uterine appendages. The uterine appendages include the fallopian tubes and ovaries. The fallopian tube, tuba ute-rina, is a paired organ that connects the uterine cavity with the abdominal cavity. It is laid along the upper edge of the broad ligament of the uterus between its sheets. The pipe diameter is not the same. It ranges from 0.5-1 to 6-8 mm. In the tube, the uterine part, pars uterina, with the uterine opening, ostium uterinum, isthmus, isthmus, ampulla, ampulla, and funnel, infundibulum are distinguished. Bo-

The ligamentous apparatus of the uterus (scheme). Connective tissue formations are depicted in green and red, peritoneal formations in blue.

1-lig. pubovesicale; 2-lig. vesicouterinum; 3-lig. cardinale; 4-lig.sacrouterinum; 5 - lig. ovarii proprium; 6 - lig.latum uteri; 7 - lig.sus-pensorium ovarii; 8-lig. teres uteri.

The funnel of the fallopian tube has fringes, fimbriae, bordering the abdominal opening of the tube, ostium ab-dominale tubae. The tube wall contains circular and longitudinal smooth muscle bundles and is capable of peristalsis. In inflammatory processes, peristalsis is disturbed: a fertilized egg can linger in the lumen of the tube and, developing (ectopic - tubal pregnancy), cause it to rupture.

The blood supply to the fallopian tubes comes from the ovarian and uterine arteries.

ovary, ovarium,- a paired organ measuring 1.5x1.5x1 cm. It is covered with germinal epithelium. With the help of the mesentery, mesovarium, the ovary is fixed to the posterior surface of the broad ligament of the uterus and lies in the deepening of the parietal peritoneum - the ovarian fossa, fossa ovarica. The uterine end of the ovary is connected with the body of the uterus through its own ligament of the ovary, lig. ovarii proprium. The tubular end of the ovary is fixed with a ligament that suspends the ovary, lig. suspensorium ovarii, to the peritoneum of the side wall of the pelvis. Under the peritoneal cover of this ligament lie the vessels of the ovary. The medial ligament that suspends the ovary, under the parietal peritoneum, contours the ureter, which creates the risk of damage during operations on the uterine appendages.

The blood supply to the ovary is carried out by a. ovarica, which originates from the abdominal aorta

at the level of the I lumbar vertebra, as well as the corresponding branches of the uterine artery. Anastomoses of the uterine and ovarian arteries are located under the own ligament of the ovary, and therefore, during surgical interventions for ectopic pregnancy, it is not recommended to clamp this ligament. The outflow of venous blood occurs in the inferior vena cava. Lymph outflow is carried out through the efferent lymphatic vessels accompanying the ovarian artery, to the lymph nodes located around the aorta, and to the iliac lymph nodes. The plexus at the base of the broad ligament of the uterus participates in the innervation of the ovary.

Vagina, vagina. The vagina is located in the anterior part of the small pelvis between the bladder and the rectum. With its upper end, the vagina surrounds the cervix, its lower end opens between the labia minora. The bottom of the bladder and the urethra are adjacent to the anterior wall of the vagina. They are tightly soldered to the vesico-vaginal septum, septum vesicovagi-nale. As a result, with ruptures of the vagina (childbirth, trauma), vesico-vaginal fistulas are often formed here. The rectum is adjacent to the back wall of the vagina. Between the part of the cervix protruding into the vagina and its walls, an

The uterus and its appendages. Blood vessels of the uterus, vagina and uterine appendages. Front cut. Back view.

1 - r.ovaricus; 2 - lig.teres uteri; 3 - r.tuba-rius; 4 - a., v. ovarica; 5 - a., v. lliaca com-munis; 6 - a., v. Shasa intema; 7 - ureter;

8 - a., v. glutea superior; 9 - m. pirifonnis;

10 - a., v. glutea inferior; 11 - a. and w. uteri-pay; 12, 22 - a., v. rectalis media; 13 - m.obturatorius intemus; 14 - a., v. pudenda intema; 15 - tuber ischiadicum; -16 -m. levator ani; 17 - corpus adiposum fossae ischiorectalis; 18 - canalis analis; l9 1-mm. sphincter ani extemus and intemus; 20-ampulla recti; 21 - vagina; 23 - cervix uteri (portio supravaginalis); 24 - ovarium; 25-lig. suspensorium ovarii; 26 - mesovarium;

27 - fimbria ovarica; 28 - fimbriae tubae; 29 - tuba uterina (ampulla); 30 - mesosalpinx;

31-lig. ovarii proprium; 32 - isthmus tubae uterinae; 33 - corpus uteri; 34 - fundus uteri.

recesses are formed - the vaults of the vagina: anterior and posterior.

The posterior arch is the deepest. From the side of the pelvic cavity, the peritoneum, descending from the posterior surface - the supravaginal part of the cervix, covers the posterior fornix of the vagina for 2 cm. In the middle (subperitoneal) section of the pelvic cavity, the vagina is separated from the rectum by the rectum

cervical-vaginal septum, septum rectovagi-nale.

The blood supply of the vagina is carried out by the vaginal branches from a. uterina and a. pudenda in-tema. The veins of the vagina form the venous plexus, plexus venosus vaginalis. The outflow of venous blood, lymphatic drainage and innervation are the same as in the uterus. The lower part of the vagina receives branches from n.pudendus.

The bone base of the pelvis is made up of the pelvic (pubic, iliac, ischial) bones, the sacrum and the coccyx. The boundary line (linea terminalis), the bone skeleton of the pelvis is divided into a large and small pelvis (pelvis major et minor).

The parietal muscles are adjacent to the inner surface of the large and small pelvis. The iliopsoas muscle (m. iliopsoas) is located in the large pelvis. In the small pelvis, the parietal muscles include the piriformis (m. piriformis), the internal obturator (m. obturatorius internus), and the coccygeal (m. coccygeus). The bottom of the pelvic cavity is formed by the muscles and fascia of the perineum. They are represented by the pelvic diaphragm (diaphragma pelvis), and the urogenital diaphragm (diaphragma urogenitale). The pelvic fascia is a continuation of the intra-abdominal fascia and is divided into parietal and visceral fascia. The parietal pelvic fascia (fascia pelvis parietalis) covers the parietal muscles of the pelvic cavity, as well as the muscles that form the bottom of the small pelvis.

The visceral pelvic fascia (fascia pelvis visceralis) forms closed receptacles for the pelvic organs, separated from the organs by a layer of loose fiber, in which the blood and lymphatic vessels and nerves pass. The organs of the small pelvis occupy a middle position and do not come into direct contact with the walls of the pelvis, from which they are separated by a layer of fiber.

The pelvic cavity is usually divided into three sections (floors): I - peritoneal (cavum pelvis peritoneale), II - subperitoneal (cavum pelvis subperitoneale), III - subcutaneous (cavum pelvis subcutaneum). In the female pelvis, the peritoneum, covering the posterior surface of the bladder, then passes to the anterior surface of the uterus at the level of its isthmus, forming a shallow vesicouterine cavity (excavatio vesicouterina). In front, the cervix and vagina are located subperitoneally. Covering the bottom, body and cervix from behind, the peritoneum descends below the cervix, covers the posterior fornix of the vagina and passes to the rectum, forming the recto-uterine cavity - Douglas space.

The recto-uterine recess is the lowest place in the abdominal cavity, which contributes to the accumulation of free blood, pus or other pathological exudates in this section.

When moving from the posterior wall of the uterus to the anterior wall of the rectum, the peritoneum first covers only its narrow section. In the upward direction, this section of the peritoneal cover gradually expands, going further to the side walls of the rectum, and at the level of the III sacral vertebra, the peritoneum covers the intestine from all sides, and above forms the mesentery of the sigmoid colon. The recto-uterine recess is laterally limited by the peritoneal folds of the same name (plicae rectouterinae), which continue to the anterior surface of the sacrum. At the base of the folds are muscle-fibrous strands (lig. rectouterinum, lig. sacrouterinum), which play an important role in fixing the uterus. On the sides of the uterus in the frontal plane are wide ligaments of the uterus (ligg.

lata uteri), which are duplications of the peritoneum. They go to the side walls of the pelvis and pass into the parietal peritoneum. In the pelvis, a periuterine cellular space is isolated - parametrium, which is located around the cervix and passes directly into the gap between the sheets of the broad ligament of the uterus. From below, it is limited by the upper fascia of the pelvic diaphragm. In the periuterine cellular space, a precervical, a retrocervical parametrium and two lateral parametriums are distinguished. The anterior parametrium is a slightly pronounced layer of tissue that separates the cervix from the bladder, the posterior parametrium is the vagina from the rectum. Conventionally, the lateral boundaries of the anterior and posterior parameters are paired ligaments running from the uterus to the pubis (pubic-uterine ligaments) and to the sacrum (sacral-uterine ligaments). The lateral parameters are located at the base of the broad ligaments of the uterus between its leaves. On the sides, the parametrium passes directly into the parietal tissue of the pelvis. In the parametric cellular space of the pelvis, the uterine artery and the ureter crossing it, the ovarian vessels, the uterine venous plexus and the nerve plexuses pass. With the formation of hematomas or abscesses in the parametric cellular spaces, the spread of the pathological process can continue into the retroperitoneal tissue (along the ureter and ovarian vessels), the tissue of the iliac fossa, the tissue of the gluteal region, and the inguinal canal.

The small pelvis is a collection of bones and soft tissues located below the border line.

The walls of the pelvis, represented by the pelvic bones below the borderline, the sacrum, coccyx and muscles that cover the large sciatic (piriformis) and obturator (internal obturator muscle) openings, front, back and sides limit the pelvic cavity. From below, the pelvic cavity is limited by the soft tissues of the perineum. Its muscular basis is formed by the levator ani muscle and the deep transverse perineal muscle, which take part in the formation of the pelvic diaphragm and the urogenital diaphragm, respectively.

The pelvic cavity is usually divided into three sections, or floors:

Peritoneal cavity of the pelvis- the upper part of the pelvic cavity, enclosed between the parietal peritoneum of the small pelvis (is the lower part of the abdominal cavity). It contains parts of the pelvic organs covered by the peritoneum - the rectum, bladder, in women - the uterus, wide uterine ligaments, fallopian tubes, ovaries and the upper part of the posterior wall of the vagina. After emptying the pelvic organs, loops of the small intestine, the greater omentum, and sometimes the transverse or sigmoid colon, and the appendix can descend into the peritoneal cavity of the pelvis.

Subperitoneal cavity of the pelvis- part of the pelvic cavity

enclosed between the parietal peritoneum and the sheet of the pelvic fascia, which covers the top of the muscle that lifts the anus. Contains blood and lymphatic vessels, lymph nodes, nerves, extraperitoneal parts of the pelvic organs - the bladder, rectum, pelvic part of the ureter. In addition, in the subperitoneal cavity of the pelvis in women there is a vagina (except for the upper part of the back wall) and the cervix, in men - the prostate gland, pelvic parts of the vas deferens, seminal

bubbles. The listed organs are surrounded by fatty tissue, divided by the spurs of the pelvic fascia into several cellular spaces.

Subcutaneous pelvic cavity- the space related to the perineum and lying between the skin and the diaphragm of the pelvis. It contains the sciatic-rectal fossa filled with adipose tissue with the internal genital vessels and pudendal nerve passing through it, as well as their branches, parts of the organs of the urogenital system, and the distal part of the rectum. The exit from the small pelvis is closed by the pelvic and urogenital diaphragms formed by muscles and fascia.

Course of the peritoneum

In the cavity of the male pelvis, the peritoneum passes from the anterolateral wall of the abdomen to the anterior wall of the bladder, covers its upper, posterior and part of the side walls, and passes to the anterior wall of the rectum, forming a recto-cystic cavity. From the sides, it is limited by the recto-intestinal vesicle folds of the peritoneum. This recess can accommodate part of the loops of the small intestine and the sigmoid colon.

In women, the peritoneum passes from the bladder to the uterus (covers mesoperitoneally), then to the posterior fornix of the vagina, and then to the anterior wall of the rectum. Thus, two depressions are formed in the cavity of the female pelvis: vesico-uterine and rectal-uterine. When moving from the uterus to the rectum, the peritoneum forms two folds that stretch in the anteroposterior direction, reaching the sacrum. The greater omentum may be located in the vesicouterine cavity; in the rectum-uterine - loops of the small intestine. Blood, pus, urine can also accumulate here in case of injuries and inflammation.

Fascia of the pelvis

The pelvic fascia is a continuation of the intra-abdominal fascia, and consists of parietal and visceral sheets.

The parietal sheet of the pelvic fascia covers the parietal muscles of the pelvic cavity and is divided into the superior fascia of the urogenital and pelvic diaphragm and the inferior fascia of the urogenital

howling and pelvic diaphragm, which contain the muscles that form the bottom of the small pelvis (deep transverse perineal muscle and the muscle that lifts the anus).

The visceral sheet of the pelvic fascia covers the organs located in the middle floor of the small pelvis. This sheet forms fascial capsules for the pelvic organs (Pirogov-Retzia for the prostate gland and Amyuss for the rectum), separated from the organs by a layer of loose fiber, in which the blood and lymphatic vessels, nerves of the pelvic organs are located. The capsules are separated by a septum located in the frontal plane (Denonville-Salishchev aponeurosis; rectovesical septum in men and rectovaginal septum in women), which is a duplication of the primary peritoneum. Anterior to the septum are the bladder, prostate gland, seminal vesicles and parts of the vas deferens in men, the bladder and uterus in women. Behind the septum is the rectum.

Pelvic cellular spaces Classification:

1. Parietal: retropubic (preperitoneal, prevesical), retrovesical, retrorectal, parametric, lateral.

2. Visceral: paravesical, pararectal, oculocervical.

Lateral cellular space-paired (right-, and

left-sided), laterally limited by the parietal fascia of the pelvis, medially by the sagittal spurs of the visceral fascia of the pelvis.

Content: internal iliac vessels and their branches, pelvic parts of the ureters, vas deferens, branches of the sacral plexus.

Ways of spread of pus:

l into the retrovesical space (along the ureter);

l into the retroperitoneal space (along the ureter);

l in the gluteal region (along the upper and lower gluteal vessels and nerves);

l into the inguinal canal (along the vas deferens).

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Retropubic space

1. prevesical space –limited in front of the forehead

kovy symphysis and branches of the pubic bones, behind - prevesical fascia.

2. preperitoneal space -between the prevesical fascia and the anterior leaf of the visceral fascia of the bladder.

Ways of spread of pus:

l into the subcutaneous fatty tissue of the thigh (through the femoral ring);

l into the tissue surrounding the medial thigh muscle group (through the obturator canal);

l in the preperitoneal tissue of the anterior wall of the abdomen;

l into the lateral cellular space of the pelvis (through defects in the sagittal spurs of the visceral fascia of the pelvis).

Paravesical space-located between walls

which is the bladder and the visceral fascia that covers it.

Content: vesical venous plexus.

Posterior bladder space– limited front to rear

with a leaf of the visceral fascia of the bladder, behind

- the peritoneal-perineal fascia, which forms the recto-intestinal-vesical septum in men or the recto-intestinal-vaginal septum in women.

Content: in men, the prostate gland, seminal vesicles, vas deferens and ureters; in women, the vagina and ureters.

Ways of spread of pus:

l in the inguinal region and scrotum (along the vas deferens through the inguinal canal);

l into the retroperitoneal cellular space (along the ureters).

Posterior rectal space– limited special

among the rectum, covered with the visceral fascia of the pelvis; behind - the sacrum, lined with parietal fascia of the pelvis.

Content: sacral parts of the sympathetic trunks, sacral lymph nodes, lateral and median sacral arteries, veins of the same name that form the sacral

venous plexus, superior rectal artery and vein.

Ways of spread of pus(along the vessels) :

l into the retroperitoneal space;

l into the lateral cellular space of the pelvis.

Perirectal space-between visceral-

noah fascia of the pelvis, covering the rectum, and its wall.

Periouterine (parametrical) space - steam-

noe ( right-, and left-sided), between the leaves of the wide uterine ligaments .

Ways of spread of pus:

l laterally and down - into the lateral space of the pelvis;

l medially and down - into the pericervical tissue;

l into the retrovesical space.

Peri-cervical space - located around the cervix.

Pelvic vessels

The walls and organs of the pelvis are supplied with blood by the internal iliac arteries, which enter the lateral cellular spaces and are divided into anterior and posterior branches. Branches depart from the anterior branches of the internal iliac arteries, supplying blood mainly to the pelvic organs:

the umbilical artery giving off the superior vesical artery;

inferior vesical artery; uterine artery - among women, in men- seminal artery

efferent duct; middle rectal artery;

internal genital artery.

From the posterior branches of the internal iliac arteries

branches that supply blood to the walls of the pelvis:

iliac-lumbar artery; lateral sacral artery; obturator artery; superior gluteal artery;

inferior gluteal artery.

The parietal branches of the internal iliac arteries are accompanied by two veins of the same name. Visceral veins form well-defined venous plexuses around the organs. There are venous plexus of the bladder, prostate, uterus, vagina and rectum. The veins of the rectum, in particular, the superior rectal vein, through the inferior mesenteric vein, flow into the portal vein, the middle and inferior rectal veins into the system of the inferior vena cava. They are connected to each other, forming porto-caval anastomoses. From other venous plexuses, blood flows into the system of the inferior vena cava.

Innervation of the pelvis sacral plexus(somatic, paired) formed

anterior branches of IV, V lumbar and I, II, III sacral spinal nerves.

Branches:

muscle branches; superior gluteal nerve;

inferior gluteal nerve; posterior cutaneous nerve of the thigh; sciatic nerve; sexual nerve.

The bone base of the pelvis is formed by two pelvic bones, the sacrum and the coccyx. The pelvic cavity is the receptacle for loops of the small and part of the large intestine, as well as the genitourinary system. The upper external landmarks of the pelvis are the pubic and iliac bones, the sacrum. The lower part is limited by the coccyx, ischial tubercles. The exit from the pelvis is closed by the muscles and fasciae of the perineum, which form the diaphragm of the pelvis.

In the region of the pelvic floor, formed by fascia and muscles, the pelvic diaphragm and the urogenital diaphragm are isolated. The diaphragm of the pelvis is formed mainly by the muscle that lifts the anus. Its muscle fibers, connecting with the bundles of the opposite side, cover the wall of the lower part of the rectum and intertwine with the muscle fibers of the external sphincter of the anus.

The urogenital diaphragm is a deep transverse perineal muscle that fills the angle between the inferior rami of the pubic and ischial bones. Below the diaphragm is the perineum.

Separate the large and small pelvis. The boundary between them is the boundary line. The pelvic cavity is divided into three sections (floors): peritoneal, subperitoneal and subcutaneous.

In women, the peritoneum, when moving from the posterior surface of the bladder to the anterior surface of the uterus, forms a shallow vesicouterine depression. In front, the cervix and vagina are located subperitoneally. Covering the bottom, body and cervix from behind, the peritoneum descends to the posterior fornix of the vagina and passes to the rectum, forming a deep recto-uterine cavity.

Duplications of the peritoneum, directed away from the uterus to the side walls of the pelvis, are called the wide ligament of the uterus. Between the leaves of the broad ligament of the uterus are the fallopian tube, the proper ligament of the ovary, the round ligament of the uterus and the ovarian artery and vein that go to the ovary and lie in the ligament that supports the ovary. At the base of the ligament lie the ureter, uterine artery, venous plexus, and uterovaginal nerve plexus. In addition to the wide ligaments, the uterus in its position is strengthened by round ligaments, recto-uterine and sacro-uterine ligaments and muscles of the urogenital diaphragm, to which the vagina is fixed.

The ovaries are located behind the broad ligament of the uterus closer to the side walls of the pelvis. With the help of ligaments, the ovaries are connected to the corners of the uterus, and with the help of suspensory ligaments, they are fixed to the side walls of the pelvis.

The subperitoneal pelvis is located between the peritoneum and the parietal fascia, it contains parts of organs that do not have a peritoneal cover, the final parts of the ureters, the vas deferens, seminal vesicles, the prostate, in women - the cervix and part of the vagina, blood vessels, nerves, lymph nodes and their surrounding loose fatty tissue.

In the subperitoneal part of the small pelvis, two spurs of the fascia pass in the sagittal plane; in front they are attached at the medial edge of the internal opening of the obturator canal, then, following from front to back, they merge with the fascia of the bladder, rectum and are attached to the anterior surface of the sacrum, closer to the sacroiliac joint. In each of the spurs there are visceral branches of vessels and nerves going to the pelvic organs.

In the frontal plane, as noted, between the bladder, prostate and rectum in men, between the rectum and vagina in women, there is a peritoneal-perineal aponeurosis, which, having reached the sagittal spurs, merges with them and reaches the anterior surface of the sacrum. Thus, the following parietal cellular spaces can be distinguished; prevesical, retrovesical, retrorectal and two lateral.

The retropubic cellular space is located between the pubic symphysis and the visceral fascia of the bladder. It is divided into preperitoneal (anterior) and prevesical spaces.

The prevesical space is relatively closed, triangular in shape, bounded anteriorly by the pubic symphysis and posteriorly by the prevesical fascia, laterally fixed by obliterated umbilical arteries. The prevesical space of the pelvis along the femoral canal communicates with the tissue of the anterior surface of the thigh, and along the course of the cystic vessels - with the lateral cellular space of the pelvis. Through the prevesical space, an extraperitoneal access to the bladder is carried out when a suprapubic fistula is applied.

The retrovesical cellular space is located between the posterior wall of the bladder, covered with a visceral sheet of the prevesical fascia, and the peritoneal-perineal aponeurosis. From the sides, this space is limited by the already described sagittal fascial spurs. The bottom is the urogenital diaphragm of the pelvis. In men, the prostate gland is located here, which has a strong fascial capsule, the end parts of the ureters, the vas deferens with their ampoules, seminal vesicles, loose fiber and the prostate venous plexus.

Purulent streaks from the retrovesical cellular space can spread into the cellular space of the bladder, into the region of the inguinal canal along the vas deferens, into the retroperitoneal cellular space along the ureters, into the urethra, and into the rectum.

The lateral cellular space of the pelvis (right and left) is located between the parietal and visceral fascia of the pelvis. The lower boundary of this space is the parietal fascia, which covers the levator ani muscle from above. Behind there is a message with the retrointestinal parietal space. From below, the lateral cellular spaces can communicate with the ischiorectal tissue if there are gaps in the thickness of the muscle that lifts the anus, or through the gap between this muscle and the internal obturator.

Thus, the lateral cellular spaces communicate with the visceral cellular spaces of all pelvic organs.

The posterior rectal cellular space is located between the rectum with its fascial capsule in front and the sacrum in the back. This cellular space is delimited from the lateral spaces of the pelvis by sagittal spurs running in the direction of the sacroiliac joint. Its lower border is formed by the coccygeal muscle.

In the fatty tissue behind the rectal space, the upper rectal artery is located at the top, then the median and branches of the lateral sacral arteries, the sacral sympathetic trunk, branches from the parasympathetic centers of the sacral spinal cord, sacral lymph nodes.

The spread of purulent streaks from the retrorectal space is possible in the retroperitoneal cellular space, lateral parietal cellular spaces of the pelvis, visceral cellular space of the rectum (between the intestinal wall and its fascia).

Operative access to the posterior rectal cellular space of the pelvis is carried out through an arcuate or median incision between the coccyx and the anus, or the coccyx and sacrum are resected no higher than the third sacral vertebra.

Vessels of the subperitoneal region

At the level of the sacroiliac joint, the common iliac arteries divide into external and internal branches. The internal iliac artery goes down - back and after 1.5-5 cm is divided into the anterior and posterior branches. The superior and inferior cystic arteries, uterine, middle rectal and parietal arteries (umbilical, obturator, inferior gluteal, internal genital) depart from the anterior branch. Parietal arteries depart from the posterior branch (ilio-lumbar, lateral sacral, superior gluteal). The internal pudendal arteries pass through the small sciatic foramen into the ischiorectal fossa.

Venous blood from the pelvic organs flows into the venous plexus (vesical, prostatic, uterine, vaginal). The latter give rise to arteries of the same name, usually double, veins, which, together with the parietal veins (superior and inferior gluteal, obturator, lateral sacral, internal pudendal) form the internal iliac vein. Blood from the rectal venous plexus through the superior rectal vein partially flows into the portal vein system.

The lymph nodes of the pelvis are represented by the iliac and sacral nodes. The iliac nodes are located along the external (lower) and common (upper) iliac arteries and veins (from 3 to 16 nodes) and receive lymph from the lower limb, external genital organs, and the lower half of the anterior abdominal wall.

Rectum

The rectum is the end part of the intestinal tube and begins at the level of II or the upper edge of the III sacral vertebra, where the colon loses the mesentery and the longitudinal muscle fibers are evenly distributed over the entire surface of the intestine, and not in the form of three ribbons. The intestine ends with an anus.

The length of the rectum does not exceed 15 cm. Anterior to it in men are the bladder and prostate, ampullae of the vas deferens, seminal vesicles and the final parts of the ureters, in women - the vagina and cervix. The rectum in the sagittal plane forms a bend according to the curvature of the sacrum, first in the direction from front to back (sacral bend), then in the opposite direction (perineal bend). At the same level, the rectum also bends in the frontal plane, forming an angle open to the right.

In the rectum, two main parts are distinguished: the pelvic and perineal. The pelvic part (10–12 cm long) lies above the pelvic diaphragm and has a nadampular part and an ampulla (the wide part of the rectum. The nadampular part of the rectum, together with the final part of the sigmoid colon, is called the rectosigmoid colon.

The anal canal (the perineal part of the rectum) is 2.5–3 cm long and lies above the pelvic diaphragm. The fatty body of the sciatic-anal fossa adjoins it from the sides, in front - the bulb of the penis, covered with muscle and fascia, the posterior edge of the urogenital diaphragm and the tendinous center of the perineum.

The rectum is covered in the upper part of the peritoneum from all sides, below - in front and from the sides, and at the level of the IV sacral vertebra (and partially V) - only in front. In the subperitoneal part, the rectum has a well-defined visceral fascia - its own fascia of the rectum.

The mucous membrane of the upper part of the ampoule of the rectum forms 2-4 transverse folds. In the anal canal, the longitudinal folds are separated by sinuses, the number of which varies from 5 to 13, and the depth is often 3-4 mm. From below, the sinuses are limited by anal flaps located 1.5 - 2 cm above the anus. The purpose of these folds is to relieve the pressure of feces on the pelvic floor.

The muscular layer of the rectum consists of the outer longitudinal and inner circular layers. The outlet part of the rectum is annularly covered under the skin by the external sphincter of the anus, consisting of striated muscle fibers (arbitrary sphincter). At a distance of 3 - 4 cm from the anus, annular smooth muscle bundles, thickening, form an internal sphincter (involuntary). Between the fibers of the external and internal sphincter, the fibers of the muscle that lifts the rectum are woven. At a distance of 10 cm from the anus, the annular muscles form another thickening - the third (involuntary) sphincter.

The arterial blood supply to the rectum is carried out mainly by the superior rectal artery (unpaired, terminal branch of the inferior mesenteric artery), which runs at the root of the mesentery of the sigmoid colon and is divided posteriorly at the level of the beginning of the intestine into 2-3 (sometimes 4) branches, which along the posterior and lateral surfaces the intestines reach its lower part, where they connect with the branches of the middle and lower rectal arteries.

The middle rectal arteries (paired, from the internal iliac artery) supply blood to the lower parts of the rectum. They may be of large caliber, and sometimes absent altogether.

The lower rectal arteries (paired) in the amount of 1-4 on each side depart from the internal genital arteries and, having passed through the tissue of the ischio-anal fossa, enter the wall of the rectum in the region of the external sphincter.

The veins corresponding to the arteries form plexuses in the wall of the rectum (rectal venous plexuses). There are subcutaneous plexus (around the anus), submucosal, which in the lower part consists of tangles of veins penetrating between bundles of circular muscles (hemorrhoidal zone), and subfascial (between the muscle layer and its own fascia). Venous outflow is carried out through the superior rectal vein (it is the beginning of the inferior mesenteric vein), the middle rectal vein (flows into the internal iliac vein), the inferior rectal vein (flows into the internal pudendal vein). Thus, in the wall of the rectum there is one of the porto-caval anastomoses.

Lymphatic vessels from the subcutaneous lymphatic network around the anus below the anal flaps are sent to the inguinal lymph nodes. From the back of this network and from the networks of lymphatic capillaries of the posterior wall of the rectum in the area of ​​​​attachment of the muscle that lifts the anus, the lymphatic vessels are sent to the sacral lymph nodes.

From the area of ​​the rectum within 5 - 6 cm from the anus, the lymphatic vessels are sent on the one hand - along the lower and middle rectal blood vessels to the internal iliac lymph nodes, on the other - along the upper rectal artery to the nodes located along this vessel, up to the lower mesenteric lymph nodes.

Lymph flows into these nodes from parts of the rectum lying above 5-6 cm from the anus. Thus, from the lower part of the rectum, the lymphatic vessels go up and to the sides, and from the upper - up.

The rectum is innervated by parasympathetic, sympathetic and spinal nerves. The sympathetic branches to the intestine come along the superior rectal artery in the form of the superior rectal plexus (from the inferior mesenteric plexus) and along the middle rectal arteries, and independently as the middle rectal plexus from the inferior hypogastric plexus. Through the same perivascular plexuses, parasympathetic branches coming from the sacral part of the parasympathetic system in the form of pelvic splanchnic nerves approach the rectum. As part of the sacral spinal nerves are sensory nerves that convey the feeling of filling the rectum.

The anal canal, external sphincter, and skin around the anus are innervated by the inferior rectal nerves, which arise from the pudendal nerve. These nerves contain sympathetic fibers that innervate the deep muscles of the rectum, and in particular the internal sphincter of the anus.

Bladder

It is located in the anterior part of the small pelvis. The anterior surface of the bladder is adjacent to the pubic symphysis and the upper branches of the pubic bones, separated from them by a layer of loose connective tissue. The posterior surface of the bladder is bordered by the ampulla of the rectum, the ampullae of the vas deferens, the seminal vesicles, and the terminal parts of the ureters. From above and from the sides to the bladder, the loops of the thin, sigmoid, and sometimes transverse colon and caecum, separated from it by the peritoneum, are adjacent. The lower surface of the bladder and the initial part of the urethra is covered by the prostate. The vas deferens adjoins the lateral surfaces of the bladder for some length.

The bladder is divided into the apex, body, fundus and neck (the part of the bladder that passes into the urethra). The bladder has well-defined muscular and submucosal layers, as a result of which the mucous membrane forms folds. There are no folds and a submucosal layer in the region of the bottom of the bladder, a triangular platform is formed here, in the front part of which there is an internal opening of the urethra. At the base of the triangle there is a fold connecting the orifices of both ureters. The involuntary sphincter of the bladder covers the initial part of the urethra, the arbitrary sphincter is located at the level of the membranous part of the urethra.

The blood supply to the bladder is carried out by the superior artery coming from the umbilical artery and the inferior artery coming directly from the anterior trunk of the internal iliac artery.

Veins of the bladder form plexuses in the wall and on the surface of the bladder. They enter the internal iliac vein. The outflow of lymph is carried out in the lymph nodes located along the vessels.

The upper and lower hypogastric nerve plexuses, the pelvic splanchnic nerves and the pudendal nerve take part in the innervation of the bladder.

Prostate

It is located in the subperitoneal part of the small pelvis, covers with its shares the initial part of the urethra. The prostate has a well-defined fascial capsule, from which ligaments go to the pubic bones. In the gland, two lobes and an isthmus (third lobe) are distinguished. The ducts of the prostate open into the prostate urethra.

The prostate is supplied by branches from the inferior cystic arteries and the middle rectal arteries (from the internal iliac artery). The veins form the prostatic venous plexus, which merges with the vesical plexus and empties into the internal iliac vein.

The pelvic part of the vas deferens is located in the subperitoneal part of the small pelvis and is directed from the internal opening of the inguinal canal downwards and backwards, forming the ampulla of the vas deferens. Behind the ampoules are the seminal vesicles. The duct of the ampoule, merging with the duct of the seminal vesicle, penetrates the body of the prostate and opens into the prostatic part of the urethra. The vas deferens are supplied with blood through the arteries of the vas deferens.

Topographic anatomy of the pelvis allows you to study the physiological features of the pelvic region in layers. These layers are conditional, used by scientists for convenience in a detailed study. What features does the topography of the pelvis have?

Bone component

If we consider topographically the bone structure of the pelvic region, then in adulthood it consists of several bones and bone elements. In childhood, the skeletal system consists of a larger number of structures, which then grow together.

The pelvis consists of bones connected in a ring horizontally:

• sacrum;
• fifth vertebra;
• coccyx;
• a pair of nameless bones.

Nameless bones - fused pubic, iliac and ischial. By the age of 25, they become monolithic, representing a single structure. The sacrum with the iliac crest of the innominate bone forms a fixed connection, while the pubic elements of the pelvis are connected by cartilage. The pelvis is connected to the lower limbs by means of the hip joints formed by their articular surface of the femoral head and the acetabulum of the innominate bones.

The bone structure is a support for the body, muscles and ligamentous apparatus are attached to the bones, and the pelvic cavity itself serves as a container for internal organs.

Multistoried pelvic cavity

The pelvis is an area that is topographically defined by the boundaries of the bones. Tissues that are outside this border are not included in this area as a topographic unit. That is, anatomically, the pelvis is a cavity bounded by the innominate bones, coccyx and sacrum, in this area the lower parts of the rectum, urinary tract and genital organs are considered. The upper border is the peritoneal tissue, the lower one is the perineum.

The pelvic region is also conditionally divided into the small and large pelvis. The large one is limited by the sacrum, iliac wings, covered with the iliopsoas muscle, it includes the peritoneum (up to the iliac fossae). The topography of the small pelvis has several floors (sections):

• peritoneal;
• subperitoneal;
• perineal.

Each department contains certain internal organs.

Peritoneal department

From above, the upper floor is formed by the region of the peritoneum, which passes to the bladder, on both sides of it there are peritoneal paravesical pits, and in the area of ​​the pubic articulation there is a transverse fold.

The same floor includes the upper zones of the vas deferens in men, in women this includes most of the uterus along with appendages. There are no other gender differences in the structure of the peritoneal pelvis.

Subperitoneal department

The second floor begins immediately above the peritoneum and is bounded from below by the pelvic fascia. In men, the abdominal region includes the following elements:

• the lower part of the bladder;
• distal rectum;
• prostate;
• ureters.

In women, instead of the prostate gland, the department contains the cervix and vagina.

Cellular space

The cellular space begins in the abdominal region, which acts as a kind of organ separator. It delimits the elements of the urinary-genital and digestive systems from the side walls of the pelvis.

The cell space that surrounds the walls of the pelvis is called parietal, the one that encircles the internal organs is called visceral. Fiber is viewed on a sagittal (vertical) section.

The wall spaces include the following areas:

1. Retropubic. The area between the symphysis pubis, the transverse fascia and the fascia of the bladder. It is divided into prevesical and preperitoneal spaces.
2. Side. Left and right cellular spaces separated by a conditional sagittal plane. Passes between the piriformis and obturator muscles and the pubic ligaments.
3. Posterior rectal. Its area begins behind the rectum and borders on the sacrum.

This classification is suitable for describing the cellular spaces of the female pelvis. In the male body, another area is distinguished - the retrovesical, which runs along the back wall of the peritoneum and borders on the visceral space of the prostate.

Fact! In all types of fiber that communicate with each other, there is a circulatory system and nerve fibers.

If we talk about the visceral cellular space, then this includes the following types:

1. Peripesical. It surrounds the bladder, while its layers in the upper region of the organ are thinner. Behind in women it is combined with the periuterine, in men - with the periprostatic space.
2. Periouterine. They are divided into pericervical, paralateral and retrocervical. The thickness is most pronounced in the cervix.
3. Peruvaginal. Divided according to the vessels of the rectum into the posterior vaginal and anterior vaginal regions.
4. Periprostatic. Surrounds the prostate gland and is combined with the perineum.
5. Perirectal. It is divided along the passing fascia into the posterior, lateral and anterior sections.

Visceral types of space communicate with each other and with anterior wall tissue.

perineal department

The perineal region, which completes the three-story structure, is bounded from above by the surface of the pelvic diaphragm. It includes the entire lower part of the internal organs (bladder and rectum) and the ischiorectal fossa.

Circulatory system

The internal iliac artery is the main circulatory element of the pelvic region. It runs along the anterior wall of the rectum to the ischial opening, where it is divided into two trunks - anterior and posterior. The first feeds the visceral arteries:

• middle rectal;
• parental;
• obturator;
• umbilical.

The posterior trunk has a more powerful structure and includes several gluteal, rectal, parietal arteries. Nutrition of the internal organs is carried out with the help of small capillaries extending from the main vessels.

If we talk about the outflow of blood, the venous bloodstream, then it originates in the internal organs and passes through the internal iliac vein, weaving into other smaller vessels.

For reference! In the pelvic cavity, lymph outflow is also carried out through the anterior wall and visceral lymph nodes.

Nerves

A group of nerve fibers departs from the piriformis muscle - the sacral plexus. Short bundles of nerves depart from it, which pass to the gluteal region. In the subpiriform foramen, the nerve fibers meet the sciatic and pudendal nerves. The latter, making a loop around the pear-shaped opening, returns to the pelvic cavity. Several more branches depart from it, which go to the area of ​​the sphincter, the perineum.

Topographic anatomy helps to gain a whole range of important knowledge about the structure of the body. It is the knowledge of physiological characteristics that allows us to understand how and why a particular disease develops.